regexguard

Regex safety & correctness analyzer -- detects catastrophic backtracking, portability errors, correctness bugs, maintainability issues, anchoring problems, and pattern injection risks

RegexGuard -- Regex Safety & Correctness Analyzer

RegexGuard scans codebases for regex anti-patterns: catastrophic backtracking (ReDoS), portability errors across engines, correctness bugs, maintainability issues, anchoring and boundary problems, and pattern injection risks. It uses regex-based pattern matching against 90 regex-specific patterns across 6 categories, lefthook for git hook integration, and produces markdown reports with actionable remediation guidance. 100% local. Zero telemetry.

Note: RegexGuard focuses on regex patterns found in source code (JavaScript, Python, Go, Java, Ruby, shell scripts, config files). It detects anti-patterns in how regexes are written, constructed, and used.

Commands

Free Tier (No license required)

regexguard scan [file|directory]

One-shot regex safety scan of files or directories.

How to execute:

bash

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [target]

What it does:

1. Accepts a file path or directory (defaults to current directory)
2. Discovers all source files (skips .git, node_modules, binaries, images, .min.js)
3. Runs 30 regex patterns against each file (free tier limit)
4. Calculates a regex quality score (0-100) per file and overall
5. Grades: A (90-100), B (80-89), C (70-79), D (60-69), F (<60)
6. Outputs findings with: file, line number, check ID, severity, description, recommendation
7. Exit code 0 if score >= 70, exit code 1 if regex quality is poor
8. Free tier limited to first 30 patterns (CB + PE categories)

Example usage scenarios:

• "Scan my code for regex issues" -> runs regexguard scan .
• "Check this file for ReDoS vulnerabilities" -> runs regexguard scan src/validators.ts
• "Find catastrophic backtracking patterns" -> runs regexguard scan src/
• "Check for non-portable regex syntax" -> runs regexguard scan .
• "Audit regex patterns for correctness" -> runs regexguard scan .

Pro Tier ($19/user/month -- requires REGEXGUARD_LICENSE_KEY)

regexguard scan --tier pro [file|directory]

Extended scan with 60 patterns covering backtracking, portability, correctness, and maintainability.

How to execute:

bash

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [target] --tier pro

What it does:

1. Validates Pro+ license
2. Runs 60 regex patterns (CB, PE, CE, MA categories)
3. Detects correctness bugs like unescaped dots, bad character class ranges
4. Identifies maintainability issues: overly complex patterns, missing comments
5. Full category breakdown reporting

regexguard scan --format json [directory]

Generate JSON output for CI/CD integration.

bash

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format json

regexguard scan --format html [directory]

Generate HTML report for browser viewing.

bash

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --format html

regexguard scan --category CB [directory]

Filter scan to a specific check category (CB, PE, CE, MA, AN, PI).

bash

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --category CB

Team Tier ($39/user/month -- requires REGEXGUARD_LICENSE_KEY with team tier)

regexguard scan --tier team [directory]

Full scan with all 90 patterns across all 6 categories including anchoring and injection.

How to execute:

bash

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --tier team

What it does:

1. Validates Team+ license
2. Runs all 90 patterns across 6 categories
3. Includes anchoring checks (missing ^/$, multiline flag gaps, \b misuse)
4. Includes pattern injection checks (unsanitized user input, DoS vectors)
5. Full category breakdown with per-file results

regexguard scan --verbose [directory]

Verbose output showing every matched line and pattern details.

bash

bash "<SKILL_DIR>/scripts/dispatcher.sh" --path [directory] --verbose

regexguard status

Show license and configuration information.

bash

bash "<SKILL_DIR>/scripts/dispatcher.sh" status

regexguard patterns

List all 90 detection patterns across all categories.

bash

bash "<SKILL_DIR>/scripts/dispatcher.sh" patterns

Check Categories

RegexGuard detects 90 regex anti-patterns across 6 categories:

Category	Code	Patterns	Description	Severity Range
Catastrophic Backtracking	CB	15	Nested quantifiers, exponential patterns, ReDoS vectors, overlapping greed	low -- critical
Portability Errors	PE	15	Non-POSIX features, engine-specific syntax, lookbehind gaps, Unicode escapes	low -- high
Correctness Errors	CE	15	Unescaped dots, bad character class ranges, greedy vs lazy, redundant quantifiers	low -- high
Maintainability Issues	MA	15	Overly complex patterns, missing comments, duplication, magic regex strings	low -- high
Anchoring & Boundaries	AN	15	Missing ^/$, \b misuse, multiline flag gaps, validation anchor bypass	low -- critical
Pattern Injection	PI	15	Unsanitized user input in regex, string concat into RegExp, DoS vectors	low -- critical

Tier-Based Pattern Access

Tier	Patterns	Categories
Free	30	CB, PE
Pro	60	CB, PE, CE, MA
Team	90	CB, PE, CE, MA, AN, PI
Enterprise	90	CB, PE, CE, MA, AN, PI + priority support

Scoring

RegexGuard uses a deductive scoring system starting at 100 (perfect):

Severity	Point Deduction	Description
Critical	-25 per finding	Severe risk (ReDoS, injection, missing validation anchors)
High	-15 per finding	Significant problem (portability bugs, correctness errors)
Medium	-8 per finding	Moderate concern (engine-specific features, maintainability)
Low	-3 per finding	Informational / best practice suggestion

Grading Scale

Grade	Score Range	Meaning
A	90-100	Excellent regex quality
B	80-89	Good patterns with minor issues
C	70-79	Acceptable but needs improvement
D	60-69	Poor regex quality
F	Below 60	Critical regex problems

• Pass threshold: 70 (Grade C or better)
• Exit code 0 = pass (score >= 70)
• Exit code 1 = fail (score < 70)

Configuration

Users can configure RegexGuard in ~/.openclaw/openclaw.json:

json

{
  "skills": {
    "entries": {
      "regexguard": {
        "enabled": true,
        "apiKey": "YOUR_LICENSE_KEY_HERE",
        "config": {
          "severityThreshold": "medium",
          "ignorePatterns": ["**/test/**", "**/fixtures/**", "**/*.test.*"],
          "ignoreChecks": [],
          "reportFormat": "text"
        }
      }
    }
  }
}

Important Notes

• Free tier works immediately with no configuration
• All scanning happens locally -- no code is sent to external servers
• License validation is offline -- no phone-home or network calls
• Pattern matching only -- no AST parsing, no external dependencies beyond bash
• Supports scanning all file types in a single pass
• Git hooks use lefthook which must be installed (see install metadata above)
• Exit codes: 0 = pass (score >= 70), 1 = fail (for CI/CD integration)
• Output formats: text (default), json, html

Error Handling

• If lefthook is not installed and user tries hooks, prompt to install it
• If license key is invalid or expired, show clear message with link to https://regexguard.pages.dev/renew
• If a file is binary, skip it automatically with no warning
• If no scannable files found in target, report clean scan with info message
• If an invalid category is specified with --category, show available categories

When to Use RegexGuard

The user might say things like:

• "Scan my code for regex issues"
• "Check for catastrophic backtracking"
• "Find ReDoS vulnerabilities in my patterns"
• "Check for non-portable regex syntax"
• "Audit regex correctness in my codebase"
• "Find regex injection risks"
• "Check if my validation regex has proper anchors"
• "Detect overly complex regex patterns"
• "Scan for regex portability problems"
• "Find unsafe dynamic regex construction"
• "Run a regex quality audit"
• "Generate a regex health report"
• "Check for unescaped dots in my patterns"
• "Find missing anchors in validation regex"
• "Check for user input in regex constructors"